Clamshell bucket



y T. CARLSON v 1,760,812

CLAM SHELL BUCKET Filed Aug. 1, 1927 I I L A2 INVENTOR 2/ i Theodore Car/.5042

. 2/ y t /0 //4L WM v V I TORNEY Patented May 27, 1930 UNITED STATES THEODORE CARLSON, OF SEATTLE, WASHINGTON CIJAIVIESHELL BUCKET Application filed August 1, 1927. Serial No. 209,812.

This invention relates to clamshell buckets such as employed for excavating and elevating material.

The object of the invention is to provide a bucket of this character which will be strong and durablein its construction and efiicient in operation.

A further object of the invention is to provide a two-line controlled bucket wherein the scoop members are adapted to be regulated for rapid and slow closing movements when excavating or taking in a load, and wherein the two line control is adapted to regulate the speed and extent of the opening movements of the bucket members for depositing the load. a

A further object is to provide a bucket wherein the controlling lines are adapted to be utilized for holding the scoops in posi tions most advantageous for digging.

A further object of the invention is to provide a bucket wherein the parts are arranged to enable the hoisting line to apply power most advantageously to effect closing movements between the scoops. e

Other objects and advantages of the invention will appear in the following description.

The invention consists in the novel construction, adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawing,-

Figure 1 is a longitudinal vertical-section of a clamshell bucket embodying the present invention the bucket being illustrated in its closed relation; Fig. 2 is a side elevation of the same illustrated in its open relation; Fig. 3 is an end elevation of the bucket when closed; Fig. 4 is a plan view of the bucket scoop members; and Fig. 5 is a detail horizontal sectional view to show the preferred manner of hingedly connecting the yoke members together. 7

In said drawing, the reference numerals 10 represent complementary scoop members which, as shown are each reinforced at its top by a transverse bar element 11 secured to the respective end wall 12 of a scoop and havguide way for a cable 29, conventionally ing side arms 13 which are secured to the respective side walls 14.

e59 Between said side arms each scoop rein- U forcement is provided with a third arm 15, hereinafter termed a closing arm, which is integral with the respective bar element 11 and from about the middle of the bar extends inwardly and upwardly of the respective scoop, the free ends of both closing arms being pivotally connected together byvmeans of a pin 16 located at the midwidth of the bucket.

Supporting said scoops are two companion yokes, one yoke for each scoop, both yokes adapted to extend into cavities 21 (Fig. 4)

provided between the side walls 14of the associated scoop and 05 set portions 13 of the side arms 13 of the scoops reinforcement.

Hinge pins 22 extending through the respective side walls 14 and the arm portions 7 13 of a reinforcing member serve to hingedly connect the end portions 20 of the yokes to the corners of the bucket. The yokes are als hingedly connected to the scoops by means of pins 23 extending through the respective T bar elements 17 and closing arms 15.

The upper ends of said yokes are pivotally connected with each other and to an apertured block 24E as by means of trunnions upon the latter engaging within the yoke bars 17 at opposite sides of the block; or, instead'of trunnions, axially aligned pins 25 (Fig. 5) may be utilized.

As shown, the pins 25 extend through bushings 27 provided in holes of said yoke bars'and into sockets provided in the block. The pins 25 in the illustrated embodiment, are secured to the respective bush ings by set pins 26, the bushings being held against lateral displacement by the provision 9 of bushing-flange elements 27 The aperture 28 of the block 24 serves as a known as the hoisting line, the lower end of which is connected to the pin 16 of the Clos we bucket is efiected by what may he termed the opening line, thesamecomprising a cable 32 provided at its lower end with an eye or ring 33 through which is reeved a sling 34i1 From said ring the sling extends as branches 35 about the inner and outer sides respective ly; of; gnidesheaves 36 and 37 provided for bothyokes whence theextremities of the sling aresecured to eye attachments 38 rigid. with the; respective buckets 10.

A s; shownthe; sheaves 36 are positioned mainly betwen, the-bar elements 17 of the respectiveyokes and the; other. guide sheaves, 37-, are positioned in Outriggers 39 connecting the main portionsv of the referred ,to bar elementswiththe bridge elements 18.

r The object of offsetting the guide sheaves 37 is v to have the ends of. the, sling branches 35 led most advantageously to the scoops for drawing the same apart when opening the bucketeither for digging'or. dumping purposes.

Besides serving.- as ofisetting supports for the guidesheaves 37, theoutriggers 39 serve as abut-ments to limit the bucket opening movements;of-thescoops,.so' that the latter is provided with a firm backingwhen the bucket islowered in its full open relationtofacilitate" digging into hard material. v

In Fig. 1;, 18 indicates bridge pieces which may be used, if desired for connecting the bar elements 17 of each yoke together near tlieirupper ends.

The-operation of? the invention is as follows;

For digging orscooping up. a load the bucket'is lowered -in its Fig. 2 relati on upon the material; cutting into the same accordingto its-hardness and the speedatwhichthe bueket'is permittedto drop. Inbeing lowcred for digging, the bucket is kept open by maintaining a tensionupon the'line 32 (Fig. 1);. Such tension upon the line 32 acts t hrough'the branches 35 thereof toretain the bucket scoopsin their relative lowered positions: substantially as shown in Fig. 2,, the

closing arms 15 being extended so that. the

axis of the-pivotalpin l6 therefor will be in orslightly below a horizontal plane inwhich ar located the axes of the hinge pieces 22 ofthe scoops 10;

Thus arranged-the closing arms coact with the opening line'connections 35 to retain-the scoops inpositions best adapted for. digging. For closing the bucket, the hoisting line 29is actuated-to swing the closing arms 15 upwardly, Whichacting as toggle links serve to draw the yokes toward each other coincidently with the swinging of the scoops about the pins 22 and 23 which hinge the scoops to the yokes. v

For elevating the bucket both of the lines 29 and 32 may be utilized.

The load carried in the bucket is discharged by slackening, more or less, the hoisting line while'maintaining more or less tension on the bucket; opening line; 32,; the action of gravitation serving to effect the opening of the bucket supplemented by the effective power which may be applied through the line 32.

The hoisting' line 29-by being guided in the apertured block 24 atthe top of the yoke assembly from the bottomof which depend the bucket scoops assures that the bucket will" be held in an upright position when under the control of the hoistiiigline.

The branches 35 of the bucket openingliue 32am guided close to the central portion, of the top of the yoke assembly by means of'the sheaves 36, hence the bucket'w'ill'also beheld in an upright position whennnder thecontrol of'the line' 32. V

p The construction, operation, and advantages of the invention will; 1t is" thought, be understood from the foregoing description.

1. In a clamshell'bucket, two scoop-members, each scoop having a reinforcing. frame scoops, and means associated with theyokes for guidin'g' the hoisting cable and the leads ofthe bucket opening cable throughthe upper portion of the'yoke assembly.

2 Ina clamshellbucket, the combination of the bucket scoops, pivotally connected yokes supporting said scoops and hingedly connectedthereto, a hoisting cable connected to both of said scoops between said hinge connections, means provided iii-proximity of th'epi'votedconnection of the yokes for guiding said hoisting cable, bucket opening cable having leads passing about'g'uide pulleys mounted upon said y'oke's, means rigid 'With the outer sides ofthe scoops-towhich the ends of said leads are connected, and means providedupon said yokes for limiting the outward movement of the respective scoops with respect to thelr hinge connections with the yokes.

with scoop members, yoke members hingedyokes for supporting said sheaves in ofi'set ly connected at their lower ends to the rerelation with the respective yokes.

spective scoops, a bucket-closing cable operatively connected to said scoops, a guide provided for said cable, means provided on said guide for pivotally connecting the upper ends of the yokes, a bucket-opening cable, guide sheaves for the bucket-opening cable, and means protruding from said yokes for supporting said sheaves in ofiset relation with the respective yokes, said sheaves supporting means being positioned to serve as stops to limit the swinging movements of the scoops with respect to the hinge connections thereof with the yokes.

4. In a clamshell bucket, the combination with the bucket scoops, of a yoke support for each scoop, said yokes being pivotally connected together at their upper ends, pins pivotally connecting the lower ends or" said yokes to the side walls of the respective scoops, frames rigid with the respective scoops and serving to reinforce the side walls thereof, arms provided on said frames and adapted to serve as toggle devices to effect movements of said yokes for swinging the scoops bodily toward and from each other, said arms also serving to swing the respective scoops about their hinge connections with the respective yokes, a hoisting line connected with both of said arms for actuating the same, and a bucket opening cable having connections with both of said scoops at the opposite sides of the hinge connections of the respective scoops from the connection of the hoisting cable with said arms.

5. In a clamshell bucket, the combination with the scoop members, scoop supporting means hingedly connected to the side walls of the respective scoops and arranged to permit movement of the scoops bodily toward and from each other, arms rigid with the respective scoops intermediate the widths of the latter, means to pivotally connect the upper ends of said arms, a bucket-closing cable connected to said pivoting means for swinging the scoops about the axes of their hinge connections with said supporting means, said cable also serving to draw said means and the scoops into bucket closing relation, and bucket opening means secured to the outer sides of said scoop members for effecting thespreading apart of the buckets and the swinging of the scoops about the axes of said hinge connections.

6. In a clamshell bucket, the combination with the scoop members, yoke members hingedly connected at their lower ends to the respective scoops, a bucket-closing cable operatively connected to said scoops, a guide provided for said cable, means provided on said guide for pivotally connecting the upper ends of the yokes, a bucket-opening cable, guide sheaves for the bucket-opening cable, and means protruding from said Signed at Seattle, Washington, this 12th day of July, 1927 EODORE 'oARLsoN. 

